Unless otherwise indicated herein, the materials described in this section are not prior art to the claims and are not admitted to be prior art by inclusion in this section.
A typical cellular wireless communication system provides numerous wireless coverage areas in which served user equipment (UE) devices can operate. Each wireless coverage area is defined by radio frequency radiation from a respective cellular base station, and each base station, together with additional network infrastructure, may provide connectivity with one or more transport networks such as the public switched telephone network (PSTN) and the Internet. With this arrangement, a UE that is positioned within a given wireless coverage area may be served by the base station defining that coverage area and may thereby engage in communication, via that base station and perhaps additional network infrastructure, with one or more other UEs, network servers, and other entities.
In an ideal arrangement, the base stations of a cellular wireless system would provide seamless coverage throughout a region, so that UEs being served by the system could move from coverage area to coverage area without losing connectivity. In practice, however, it may not be possible to operate a sufficient number of base stations or to position the base stations in locations necessary to provide seamless coverage. As a result, there may be holes in coverage.
One way to help solve this problem is to install a wireless relay that extends the range of a base station's coverage area so as to partially or completely fill a coverage hole. Such a relay may be configured with a wireless backhaul interface for communicating with the base station in much that same way a UE does, and a wireless access interface for communicating with and serving one or more UEs in much the same way that a base station does. The relay may further include control logic for actively bridging the backhaul communications with the access communications. The relay may thus receive and recover downlink communications from the base station and transmit those communications to UEs, and receive and recover uplink communications from UEs and transmit those communications to a base station.
Advantageously, a relay base station can have a relatively small form factor, with antenna height lower than the donor base station and with reduced transmit power requirements.
Consequently, a cellular wireless service provider may conveniently employ such relay base stations throughout a region to efficiently fill coverage holes and help improve service quality.
Typically, a base station with which a wireless relay communicates is referred to as a donor base station, and the wireless relay itself is referred to as a relay base station. Further, the wireless communication link between the relay base station and the donor base station is then referred to as a relay backhaul link, and the wireless communication link between the relay base station and UEs is referred to as a relay access link. Similarly, the wireless communication link between the donor base station and UEs is referred to as the donor access link.